Video recordings of live events are now commonplace: sporting events, gamblers in casinos at the various gaming tables, shoppers in stores, passengers moving through airports and bus terminals, etc. Most frequently the recorded data is analyzed only visually by the viewer, either as the event is taking place, or later, for example after a theft has taken place from a store. Sporting events are recorded and played back by coaches and players for analysis of athletic form. For example, football training camps are recorded on video and played back to evaluate individuals' skills and play execution. It would be useful to be able to analyze the data systematically by methods other than simply viewing the video.
Sometimes individual frames of the video are printed, providing an image of one moment in time over a period of motion. The prior and post action cannot be seen in the single image. It would be desirable to simultaneously show multiple moments in time on a single image.
It is also desirable to determine the velocity or acceleration of an object. For example, in an effort to determine how quickly an athlete moves from one position to another, a coach uses a stopwatch to time the athlete from start to finish. However, stopwatch measurements can be inaccurate. It would be desirable to accurately determine velocity and acceleration from a video recording, especially in the event the athlete cannot be easily timed while performing, for example in a game situation.